It will be more useful perhaps to examine the scaling of these quantities with the Reynolds number \(Re\) , since theoretical predictions exist for such scalings for wall-bounded shear flows [1]}. Figure REF  plots these quantities as a function of Re, the symbols are the same as in figure REF . For the quantities \(\tau _{w}\) , \(u_{\tau }\) , \(\delta _{w}\) , and \(c_{f}\)  our results give the exponents \(1.46\) , \(0.75\) , \(-0.86\) , and \(-0.46\) .
For a laminar boundary layer over a flat plate, the theoretically predicted `classical' exponents for these quantities are \(3/2\) , \(3/4\) , \(-1\) , and \(-1/2\)  respectively. One sees that within the experimental uncertainties there is an excellent agreement between the present experiment and the theoretical predictions for all the wall quantities except for \(\delta _{w}\) , which is a bit smaller.
For reference, the previous measurement in rectangular cell gives \(1.55\) , \(0.8\) , \(-0.91\) , and \(-0.34\)  for the corresponding quantities [2]}.
